1. Field of the Invention
The present invention relates to a rotational operation mechanism that performs a rotation movement in response to the operation of a user, and more particularly relates to a rotational operation mechanism that can be preferably employed as a portion of what is known as a disc jockey (DJ) apparatus.
2. Description of the Related Art
In what is known as a DJ apparatus, a disc such as a compact disc (CD) is inserted into the DJ apparatus via a disc insertion opening. A round operation portion known as a jog dial is provided on an operation panel. When the jog dial is manually rotated by a user, various playback instructions such as playback and search are input.
In the rotational operation mechanism of a conventional jog dial, a sliding face known as a jog stay is fixed to the DJ apparatus body and a ring-shaped sliding member known as a jog ring is formed integrally with the jog dial and positioned so as to face the jog stay. When the user rotates the jog dial, the sliding face of the jog stay and the jog ring slide reciprocally, thereby enabling the jog dial to rotate.
In order to allow the jog dial to rotate smoothly, it is necessary to bias the jog ring in a vertical direction against the jog stay with an appropriate degree of force. If the biasing force is too strong, the friction generated between the jog ring and the jog stay is too great and rotation becomes difficult. If, on the other hand, the biasing force is too weak, then looseness occurs in the vertical direction and in the peripheral direction between the jog ring and the jog stay, and smooth operation becomes impossible. Therefore, in a conventional DJ apparatus, the jog ring is biased against the jog stay by employing a configuration in which the jog stay is vertically sandwiched between two jog rings using a combination of screws and springs.
In the above conventional configuration, however, since the jog ring is biased against the jog stay using the springs, it is necessary to employ a configuration in which both the top and bottom faces of the sliding face of the jog stay are sandwiched by two jog rings forming sliding members. As a result, the rotational operation mechanism becomes complicated, giving rise to the problem that the assembly process is quite complicated. In addition, there is such a tendency in rotational operation mechanisms utilizing a sliding member that the frictional resistance at the sliding face is relatively large, giving rise to the problem that smooth rotation cannot be obtained.